Device and Method for Forming Bundles of Individual Packages

ABSTRACT

A bundling machine comprises a transporter that conveys the bundle along a transport direction, a wrapper that receives the bundle from the transport direction and that is configured to surround the bundle with a paper cutout as the bundle proceeds along the transport direction through the wrapper such that a front end and a rear end of the paper cutout overlap, and a tensioner that is configured to be brought into engagement with the paper cutout to temporarily apply a tension to the rear end against the transport direction so as to cause the rear end to be held taut against the front end.

RELATED APPLICATIONS

This is the national stage of international application PCT/EP2020/069698, filed on Jul. 13, 2020, which claims the benefit of the Jul. 31, 2019 priority date of German application DE 102019120679.0, the contents of which are herein incorporated by reference.

FIELD OF INVENTION

The invention relates wrapping a bundle of containers with a cutout.

BACKGROUND

It is known to wrap containers with plastic film and to then heat the film to shrink it, thus forming a stable bundle of containers. However, the use of plastic for packaging is increasingly frowned upon for environmental reasons.

A difficulty that arises when using more environmentally-friendly substitutes is the inability to shrink wrap. This results in containers that are not secured well enough to promote stability of the bundle.

The foregoing difficulty can be overcome by use of a material that has inherent stability, such as cardboard. However, such materials are expensive and bulky.

SUMMARY

An object of the invention is that of wrapping a bundle of containers with a non-shrinkable and environmentally-friendly material.

In one aspect, the invention features an apparatus for wrapping a bundle of containers. The apparatus includes a tensioner that can be brought into engagement with the cutout formed from paper and that temporarily applies a tension to the cutout's rear end in a direction against the bundle's transport direction.

By means of the wrapper of the device according to the invention, the bundle of grouped individual packages is wrapped into the cutout formed from or consisting of a paper material, wherein, in the transport direction of the bundle specified by the transporter, the rear end of the cutout is guided around the bundle and brought in contact with the front end of the cutout. In order to produce a bundle formed as a stable packaging unit, with which the individual packages are secured in their relative positions to one another by the packaging, the device according to the invention a tensioner, which at least temporarily pretensions the rear end of the cutout, folded over, against the transport direction specified by the transporter, and into the direction onto the front end of the cutout. A defined degree of pretension ensures that the cutout is in taut contact with the bundle in the circumferential direction specified by the transport direction, which is a precondition for producing a stable bundle. The pretensioning prevents free spaces which influence the stability from forming in the region between the individual packages and the cutout. The pretension produced by the tensioner can in this situation be put into effect both by an active displacement of the folded rear end against the transport direction into the direction onto the front end, as well as by an only temporary local fixing of the folded rear end, wherein the pretension then results from the displacement of the bundle caused by the transporter along a transport plane.

The device according to the invention therefore allows for the production of stable bundles without the use of plastic films. By means of the tensioner a defined pretension of the cutout can be applied which is sufficient to secure the individual packages in their positions relative to one another with a paper cutout pretensioned in this manner.

The individual packages are preferably each filled at least partially with the object(s) to be taken up by the individual packages, such as a liquid. In other words, the individual packages are preferably at least partially filled packages.

Liquid containers in this case should be understood to mean the known primary packages for beverages and liquid foodstuffs, such as, in particular, bottles, cans, beakers, and pouches, or cubic packaging with or without spouts. These liquid containers can consist of one of more known materials, such as glass, plastic, metal, or cardboard.

Advantageously, during the transport through the wrapper, the bundle stands with its underside at least partially on the front end of the paper cutout, such that, during the transport of the bundle through the wrapper, the front end of the paper cutout is arranged between the underside of the bundle and the transport plane.

The arrangement of the tensioner on the device can be optional, as long as it can be ensured that the rear end is in contact with front end under tension of the paper cutout. According to a particularly advantageous embodiment of the invention, provision is made in this situation for the tensioner to be arranged adjacent to the side of the transporter facing away from the bundle.

According to a further embodiment of the invention, the tensioner is arranged opposite the transporter, which transports the bundle, for example on a transport band, standing partially or fully upright, through the wrapper, beneath the transport plane established by the transport band of the transporter.

Subject to the reservation of a divergence in the description, in this situation a transport band is understood to be any conveying means, or a plurality of conveying means, arranged transversely to the direction of transport, suitable for conveying the group of individual packages, with or without a carrying element beneath them, such as a tray, a cardboard cutout, or the like, in the transport direction.

In this situation, the front and rear ends of the paper cutout, related to the position of use, are in contact with underside of the grouped individual packages, which are particularly preferably arranged on a underlay, such as a tray made of cardboard. An adequate locationally fixed positioning of the front end results, if possible, from the own weight of the individual packages, which secure the front end in a clamping effect in the region between the transport band and the bundle. This is supplemented by the possibility of fixing the front end to the underside of the bundle by adhesive means. By means of the tensioner, which is in engagement with the rear end of the cutout wrapping the bundle, it is then possible in a convenient manner for a taut contact with adequate tension to be applied onto the paper cutout, such that this is then in close contact in a circumferential direction corresponding to the transport direction. The rear end of the paper cutout can then be secured, while maintaining an adequate pretension, to the underside of the grouped individual packages, preferably to the underside of a paper cutout.

The guiding of a region of the rear end of the paper cutout into the tensioner in such a way that it applies tension to the paper cutout can in principle be in any desired manner. According to a particularly advantageous embodiment of the invention, however, provision is made for the wrapper to comprise a guide rod which wraps the bundle into the paper cutout, and which is formed in such a way that it brings the paper cutout, in the region of its rear end, into contact with the tensioner. The use of the guide rod to transfer the region of the rear folded end of the paper cutout into the tensioner makes it possible for additional components on wrapper to be avoided. The movement path of the guide rod guiding the paper cutout around the bundle is advantageously synchronised with the tensioner in such a way that it brings the paper cutout into engagement with the tensioner in the region of its rear end, where it is then taken up by the tensioner and can be pretensioned in such a way that a taut contact of the paper cutout is established on the bundle.

In this way the movement path of the guide rod and/or of the tensioner can be aligned in relation to the movement path of the guide rod in such a way that the paper cutout is transferred into the tensioner by a stroking movement of the guide rod. As a result, a reliable interaction can be ensured of the tensioner with the paper cutout, and therefore a reliable taut arrangement of the paper cutout on the bundle.

According to a further embodiment of the invention, provision is made for the guide rod to comprise compressed air holes, in connection with a compressed air source, for displacing the paper cutout in the direction onto the tensioner. According to this embodiment of the invention, the guide rod has one or more compressed air openings, which are connected to a compressed air source. This embodiment of the invention allows the guide rod to be subjected to compressed air when it is arranged with the paper cutout in contact in the region of the tensioner. The imposition of compressed air on the guide rod leads to the paper cutout in contact with the guide rod being displaced by the compressed air emerging from the compressed air openings in the direction onto the tensioner, where it is then gripped by the tensioner and can be pretensioned against the transport direction of the grouped individual packages. The use of compressed air openings in accordance with this further embodiment of the invention ensures in a particularly reliable manner an interaction of the tensioner with the paper cutout, and therefore a taut arrangement of the paper cutout on the grouped individual packages.

As an addition or alternative to the displacement of the guide rod into the tensioner, provision is made according to a further embodiment of the invention for a separate positioning unit at the device, which can be brought with the paper cutout in the region of its rear end into an effect connection, such that a displacement of the rear end of the paper cutout into the tensioner takes place. The use of a preferably stationary separate positioning unit, independent of the wrapper and the transporter allows for an adjustment of the wrapper for the positioning of the paper cutout in the tensioner to be avoided. The positioning unit can in this case be arranged independently of the wrapper, in an optimum position on the device for the transport of the paper cutout into the tensioner, and therefore ensures, in a particularly reliable manner, the interaction of the paper cutout with the tensioner.

The configuration of the positioning unit for the displacement of the paper cutout into the tensioner can in principle be of any desired type. There is the possibility, for example, of displaceable pressure elements to be provided at the positioning unit, which move the paper cutout in the direction onto the tensioner. According to a particularly advantageous embodiment of the invention, however, provision is made for the positioning unit for displacing the rear end of the paper cutout into the tensioner to comprise a compressed air opening which is in connection with a compressed air source, preferably a row of nozzles.

According to this embodiment of the invention, the positioning unit comprises at least one compressed air opening, directed in the direction onto the tensioner, preferably a row of nozzles, such that, in the situation of an arrangement of the paper cutout in the paper cutout in the region between the positioning unit and the tensioner, by the imposing of compressed air via the compressed air opening the paper cutout can be moved in the direction onto the tensioner. This embodiment of the positioning unit is characterized in that it is possible to do away entirely with any moving parts at the positioning unit, as a result of which faults can be avoided in a particularly advantageous manner, and maintenance measures can be minimized.

The configuration of the working connection of the paper cutout in the region of its front end with the tensioner in such a way that it can exert a pretension into the paper cutout is in principle freely selectable. According to one advantageous further embodiment of the invention, however, provision is made for the tensioner to comprise a clamp and/or a suction device for securing the paper cutout in the region of its rear end. According to this further embodiment of the invention, the tensioner causes an at least temporary local securing of the paper cutout relative to the bundle wrapped with the paper cutout and moving along the transport plane in the transport direction. Even a temporary securing of the rear end already has the effect that a tension is exerted on the paper cutout, due to the simultaneous continuous movement of the bundle. The duration of the securing of the paper cutout by the tensioner depends in this case on the material properties of the paper cutout being used, since this must not exceed a tension which could lead to damage to the paper cutout. Due to this, the securing of the paper cutout in the tensioner is imposed for only a limited period of time, and/or the securing of the paper cutout in the tensioner takes place in such a way that it is guided out of the tensioner with the pretension being maintained in relation to the transporter, in order to exert an adequate tension on the paper cutout for an extended period. The securing of the paper cutout in the tensioner can be applied in this case by means of a clamp, with which the paper cutout is secured at the tensioner by clamping. In addition, or according to an alternative embodiment of the invention, the tensioner comprises a suction device, by means of which the paper cutout is held in the region of its inner end by a suitable suction device in the tensioner.

The configuration of the suction device is in principle freely selectable in this situation. According to one advantageous embodiment of the invention, however, provision is made for the suction device to comprise, in the contact region with the paper cutout, a contact surface comprising several suction openings which are in connection with a source of negative pressure. According to this embodiment of the invention, the paper cutout is held suction to the contact surface in the region of its rear end by way of the suction openings arranged in the contact surface, wherein, depending on the degree of negative pressure and the number of suction openings, the holding force of the tensioner in relation to the paper cutout can be determined. In addition to this, a configuration of the paper cutout also provides the possibility for the friction coefficient of the paper cutout to be determined in relation to the contact surface, in order to exert a suitable pretension onto the paper cutout.

In addition to the arrangement of a stationary contact surface with suction openings in accordance with the foregoing further embodiment of the invention, provision is made according to a further embodiment of the invention that the contact surface is formed on a transport band circulating in the contact region with the paper cutout against the transport direction of the bundle. According to this embodiment of the invention, it is not only the suction device which exerts a holding function on the paper cutout. In addition to this, the circulating transport band, which due to the suction device is in flat surface contact with its contact surface on the paper cutout, exerts an additional tension onto the paper contact, which results from the movement of the transport band against the transport direction of the bundle in the contact region with the paper cutout. By means of the selection of the surface of the transport band, its speed of movement, and the negative pressure imposed by means of the negative pressure source, it is possible in this situation for the holding force exerted on the paper cutout to be determined in a particularly exact manner. This can therefore be adjusted in such a way that an adequate pretension is attained, but at the same time any damage to the paper cutout due to excessive tension is avoided.

As an alternative or in addition to the suction device, the tensioner comprises a clamp, by means of which the paper cutout can be secured in the tensioning device by clamping in the region of its rear end. According to an advantageous further embodiment of the invention, in this situation the clamp comprises a first clamping element with a first contact surface and a second clamping element with a second contact surface, which can be brought into contact with the paper cutout on opposing sides. According to this embodiment of the invention, the clamping force applied to the paper cutout by the clamping elements exerts a tension on the paper cutout due to the bundle moving continuously in the transport direction. By way of the degree of the clamping force, which can be determined, for example, by the spacing interval between the clamping elements, their surface characteristics, and by the contact length between the paper cutout and the clamping elements, it is therefore possible for the tension applied to the paper cutout to be determined in a particularly exact manner. In this situation, the clamp is configured in such a way that it ensures a continuous flow of the paper cutout held under tension out of the clamp in the direction onto the bundle, in order to avoid any material damage to the paper cutout.

In order to adjust the holding force of the clamp, provision is made according to an advantageous embodiment of the invention that the spacing interval between the contact surfaces is adjustable. For this purpose, at least one clamping element can be adjusted in its spacing interval to the other clamping element, as a result of which the clamping force and holding force exerted by the clamp onto the paper cutout can be adjusted in a convenient manner.

The configuration of the clamping elements is in principle freely selectable, wherein, in particular, a reliable tension is exerted on the paper cutout by way of its surface characteristics and the resultant adhesion friction coefficient between the paper cutout and the holding element while the paper cutout is in engagement with the clamping elements and is flowing continuously out of the clamp in the direction onto the bundle. According to a particularly advantageous embodiment of the invention, provision is made for the contact surface of the first and/or second clamping elements to be formed by a brush body. The use of a brush body is characterized in particular in that, with the simultaneous application of a suitable holding force for producing a pretension onto the paper cutout, it is ensured that the paper cutout is held under tension continuously, after being taken up in the clamp and during the further transport of the bundle, until it is guided out of the clamp. According to this further embodiment of the invention, in this situation only one clamping element or both clamping elements can be configured as brush bodies. By means of the spacing interval of a brush body from, for example, a flat contact surface, or of both brush bodies, it is possible in this situation for the holding force to be reliably determined.

According to a further embodiment of the invention, provision is made for the first and/or second clamping element to be formed as rotation bodies, and in this way to be rotatable about a longitudinal axis running transverse to the transport direction, and that the first and/or second contact surfaces are adjusted in a direction opposed to the transport directions. According to this embodiment of the invention, provision is made that the contact surface of the contact element which is formed by the circumferential surface of the rotation body exerts a movement in the region of the paper cutout which is directed against the transport direction of the bundle, as a result of which a suitable pretension can be exerted onto the paper cutout.

Particularly advantageously, in this situation provision can be made for the first and/or second clamping element to comprise a cutout opening for the temporary reception of the guide rod. According to this further embodiment of the invention, the guide rod, within the framework of its movement path during the wrapping of the grouped individual packages, passes together with the paper cutout into a cutout opening provided for this purpose at the first or second clamping element, such that the paper cutout is brought particularly reliably into engagement with the first or second clamping element. In the case of the configuration as a rotation body, in this situation the rotation movement of the clamping element is matched to the movement sequence of the guide rod in such a way that it passes into the cutout opening for the transfer to the tensioner, and in the further sequence is moved together with the cutout opening in such a way that, after the transfer, the guide rod is moved out of the cutout opening. The configuration of one or both clamping elements with a cutout opening ensures a particularly reliable transfer of the paper cutout to the tensioner.

According to a further embodiment of the invention, provision is further made that the tensioner comprises a sensor unit for detecting a tension being applied onto the paper cutout. By means of the sensor unit it is therefore possible to determine the tension being applied. Excessive degrees of tension, which could lead to damage of the paper cutout, can therefore be identified in good time, so that suitable measures can be taken to reduce the holding force being applied by the tensioner.

According to a further embodiment of the invention, provision is made for the device to comprise a closure unit for securing the rear end of the paper cutout to the front end of the paper cutout. By means of the closure unit, the paper cutout which is under tension can be fixed in the region of its rear end to the front end, such that it is ensured that, after leaving the wrapper in the transport direction, the paper cutout is in contact taut on the bundle, such that a bundle formed as a stable packing unit is produced.

The configuration of the closure unit, by means of which the rear end of the paper cutout is secured to the front end, is in principle in this case freely selectable. According to a particularly advantageous embodiment, the closure unit comprises an adhesive unit and/or a strapping unit. The adhesive unit can in this situation be a device, for example, by means of which the adhesive is applied in the region between the front and rear ends of the paper cutout, such that they are secured to one another. As an alternative, the adhesive unit can also be configured so as to apply an adhesive strip, by means of which the front end of the paper cutout is fixed to the rear end of the paper cutout. An advantageously provided strapping unit allows for the fixing of the front end of the paper cutout to the rear end of the paper cutout by suitable strapping means, such as closure straps, which are tensioned around the individual packages wrapped into the paper cutout in such a way that a reliable securing of the front end of the paper cutout to the rear end of the paper cutout is ensured.

With one advantageous further embodiment of the invention, a storage unit is provided in which the paper material is stored. The paper material can be stored in the form of ready cut paper cutouts, preferably stacked above one another. As an alternative, the paper material can be stored in the storage unit in the form of a continuous material web, in particular in the form of a roll. In the latter case, provision is advantageously made also for a cutting unit for cutting the continuous material web into individual paper cutouts.

With the method according to the invention for forming bundles from individual packages, in particular liquid containers, by wrapping a bundle of grouped individual packages into a cutout of packaging material, provision is made for the following method steps. The bundle of grouped individual packages, i.e., positioned and aligned in relation to one another, is first transported by means of a transporter into the wrapper. Here the bundle is next wrapped, in a transport direction of the transporter, by the cutout formed from a paper material, hereinafter also referred to as the paper cutout. Next, the rear end of the paper cutout wrapped around the bundle is arranged overlapping onto the front end of the paper cutout.

The method according to the invention is characterized in that the rear end of the paper cutout is at least temporarily pretensioned by means of a tensioner, against the transport direction of the bundle, in the direction onto the front end of the paper cutout.

The application of a pretension onto the paper cutout by means of the tensioner can already result from a configuration of the tensioner in which the paper cutout is secured in the region of its rear end to the tensioner in such a way that it is conveyed held under tension in the transport direction of the grouped individual packages. By means of the tensioning device, a tension is therefore applied to the paper cutout, which ensures that the paper cutout, in the transport direction of the grouped individual packages is in contact as far as possible free of play, and therefore taut, on the grouped individual packages. As a result of this, a bundle can be produced which is formed as a stable packaging unit, with which the individual packages are reliably secured in their position relative to one another. In order to maintain the tension in this situation, at the end of the wrapping process the rear end of the paper cutout is fixed overlapping to the front end of the paper cutout. According to an advantageous further embodiment of the method, this can be done by means of a closure unit, which comprises an adhesive unit for the adhesive bonding of the front and rear ends of the paper cutout, and/or a strapping unit for fixing the front and rear ends of the paper cutout by a strapping means.

According to a further embodiment of the method, provision is made for the grouped individual packages to be grouped on an underlay, in particular a cardboard tray, before the transport into the wrapper. According to this embodiment of the invention, provision is made for the grouped individual packages to stand upright on a common underlay. The use of such an underlay makes it possible first for the front end of the paper cutout to be fixed to the grouped individual packages, namely the flat underlay. Following this, it is then possible, by means of the tensioner, for a tension to be reliably applied to the rear end of the paper cutout, such that a taut contact of the paper cutout to the grouped individual packages is achieved. The use of an underlay, in particular of a cardboard tray, therefore, allows for the possibility of producing a stable packaging unit, wherein, in particular, a cardboard tray supplementing the paper cutout forms an ecological packing, and allows for a reliable flat surface connection of the rear end to the front end.

According to a further embodiment of the invention, provision is made for the wrapper to comprise a guide rod, which brings the paper cutout, in the region of its front end, into engagement with the tensioner. According to this embodiment of the invention, the guide rod used to wrap the grouped individual packages into the paper cutout is further used to bring the paper cutout, in the region of its rear end, into engagement with the tensioner. This embodiment of the invention ensures in a reliable manner that the paper cutout is pretensioned by the tensioner, and therefore that a bundle formed as a stable packaging unit can be produced.

According to a further embodiment of the invention, provision is made for the rear end of the paper cutout to be moved by means of a separate positioning unit, which can be brought into an effect connection with the paper cutout in the region of the rear end, into the tensioner. The use of a separate positioning unit allows, independently of the wrapper, for a reliable movement of the paper cutout to be ensured, in the region of its rear end, into the tensioner. According to this embodiment of the invention, no adjustments are required to the wrapper, in particular to the guide rod.

The locking or securing of the rear end of the paper cutout in the tensioner in such a way that this results in a tension being applied onto the paper cutout can in principle be effected in any desired manner. According to a particularly advantageous embodiment of the invention, however, provision is made that the rear end of the paper cutout be locked in the tensioner by clamping or by means of suction force.

Locking is understood in this situation to be an arrangement of the paper cutout in the region of its rear end in the tensioner, in which, by temporary securing, a displacement of the paper cutout against the transport direction of the grouped individual packages is incurred, and/or by a reduction of the displacement speed of the rear end of the paper cutout in relation to the transport speed by the transporter tension is applied to the paper cutout, as a result of which it passes to the grouped individual packages in taut contact. According to a particularly advantageous embodiment of the invention, provision is made for the front end of the paper cutout to be locked in the tensioner by clamping or by means of suction force, as a result of which a particularly reliable securing of the paper cutout and monitoring of the tension being applied to the paper cutout can be achieved.

BRIEF DESCRIPTION OF THE FIGURES

These and other features of the invention will be apparent from the following detailed description and the accompanying figures in which:

FIG. 1a shows a first embodiment of a bundling machine for wrapping a bundle in a paper cutout;

FIG. 1B shows the bundling machine of FIG. 1A with the cutout's rear end clamped.

FIG. 2A shows a second embodiment of a bundling machine for wrapping a bundle in a paper cutout;

FIG. 2B shows the bundling machine of FIG. 2A with the cutout's rear end being released.

FIG. 3A shows a third embodiment of a bundling machine for wrapping a bundle in a paper cutout;

FIG. 3B shows the bundling machine of FIG. 3A as the front end of the cutout approaches the opening between the transport bands;

FIG. 4A shows a fourth embodiment of the bundling machine;

and

FIG. 4B shows the fourth embodiment of FIG. 4A at another instant of the bundling process.

DETAILED DESCRIPTION

FIG. 1a shows a bundling machine 1 a for forming a bundle 2 of liquid-filled containers. The bundling machine 1 a includes a transporter 10, a wrapper 6, and a tensioner 8 a. The transporter 10 moves the bundle 2 through the wrapper 6 along the transport direction 7. While the bundle 2 is within it, the wrapper wraps the bundle 2 with a paper cutout 3. The transporter 10 comprises first and second transport bands 12 a, 12 b separated by an inter-band opening 27.

The containers in the bundle 2 stand upright as the bundle 2 travels through the wrapper 6. A section of the bundle's underside is on the paper cutout's front end 5. As a result, the paper cutout's front end 5 is arranged between the bundle's underside and the first transport band 12 a during transport into the wrapper 6.

Within the wrapper 6, a guide rod 9 engages the paper cutout's rear end 4 and guides it through the inter-band opening 27. For ease of exposition, the guide rod 9 is shown at two positions in FIG. 1a , one above and one below the plane defined by the first and second transport bands 12 a, 12 b.

The tensioner 8 a lies below the transporter 10 on the side opposite that which carries the bundle 2. The tensioner 8 a temporarily fixes the paper cutout's read end 4 to thereby cause tension that holds the paper cutout 3 taut on the bundle 2.

The tensioner 8 a includes a clamp 13 a having a pivoting clamp element 19 a and a fixed clamp element 19 b. The guide rod's movement path is such that it brings the paper cutout's rear end 4 into contact with a first contact surface 21 a of the pivoting clamp element 19 a. As a result, the paper cutout's rear end 4 comes into engagement with the clamp 13 a.

Referring now to FIG. 1b , the pivoting clamp element 19 a then pivots such that the paper cutout's rear end 4 is now clamped between the first contact surface 21 a and a second contact surface 22 a, which is that of the fixed clamp element 20 a. As the bundle 2 continues to move with the rear end 4 clamped, a tension is applied to the rear end 4, thus holding the paper cutout 3 taut contact around the bundle 2.

As the bundle 2 continues to move in the transport direction, the rear end 4 will eventually overlap the front end 5. At this point, an adhesive is applied to the bundle's underside through the inter-band opening 27. The paper cutout's rear end 4 also comes undone from the clamp 13 a. The tension exerted by the clamp 13 a is selected to be insufficient to destroy the paper cutout 3 but sufficient to keep the paper cutout 3 taut against the bundle 2.

FIGS. 2a and 2b show an alternative embodiment of a bundling machine 1 b having a different tensioner 8 b and a different configuration for transferring the paper cutout's rear end 4 into the tensioner 8 b. In particular, the tensioner 8 b omits the clamp 13 a.

The illustrated tensioner 8 b features a transport band 18 having a contact surface 17. Suction openings on the contact surface 17 connect to a negative-pressure source 15 via a line 16. In this embodiment, suction draws the paper cutout's rear end 4 onto the contact surface 17. The maximum tension is thus controlled by the extent of the negative pressure.

The tensioner 8 b also features a band drive 28 that moves the contact surface 17 against the transport direction 7. As a result, the rear end 4 also sustains a holding force caused by the contact surface's movement. This holds the paper cutout 3 taut against the contact surface 17 at a predefined tension. As the bundle 2 continues to move, the rear end 4 slides out of the tensioner 8 b, as shown in FIG. 2b , until it overlaps the front end 5 on the bundle's underside.

The embodiment shown in FIGS. 2a and 2b also includes a compressed-air source 26 that connects to the guide rod 9 via a compressed-air line 16. Openings along the guide rod 9 release compressed air delivered from the compressed-air source 26. This ensures that the rear end 4 engages the contact surface 17. The compressed air from the guide rod 9 also displacing the paper cutout 3 in the direction of the contact surface 17.

As was the case with the first embodiment of the bundling machine 1 a shown in FIGS. 1a and 1b , the front end 5 and rear end 4 overlap on the bundle's underside. When this occurs, an adhesive unit applies adhesive to fix them together.

FIGS. 3a and 3b show a third embodiment of a bundling machine 1 c having a clamp 13 b that comprises first and second clamping elements 19 b, 20 b spaced apart from each other. Each clamping element 19 b, 20 b comprises corresponding brush bodies 23 a, 23 b having bristles directed towards one another. In this embodiment, as the guide rod 9 passes the rear end 4 between the clamping elements 19 b, 20 b, the brush bodies 23 a, 23 b load both sides of the rear end 4, thus applying a tension.

An actuator 29 connected to the second clamping element 20 b adjusts the space between the first and second clamping elements 19 b, 20 b. As a result, the load on the paper cutout 3 is adjustable.

As was the case in earlier embodiments, the paper cutout 3 is held under tension as the bundle 2 moves in the transport direction 7. After the rear end 4 overlaps the front end 3, the rear end 4 is fixed to the front end 5.

FIGS. 4a and 4b show an embodiment in which the first fixed clamping element 19 c comprises a first contact surface 21 c. The second clamping element 20 c comprises a rotating brush 23 c that has bristles contacting the first contact surface 21 c. A gap between the brush 23 c and the contact surface 21 c determines a holding force on the paper cutout's rear end 4. An actuator 29 adjusts this gap and thus adjusts the holding force.

The rotating brush 23 c includes a cutout opening 24 that extends along the brush's axis of rotation and has a circumferential extent. The rotation of the second clamping element 20 c is synchronized with the guide rod's movement in such a way that the rod 9 fits into the cutout opening 24 and, while there, transfers the paper cutout's rear end 4 to the clamp 13 c, as shown in FIG. 4a . The holding force that arises on the paper cutout 3 between the first and second clamping elements 19 c, 20 c holds the paper cutout 3 under tension, thus causing taut contact between the paper cutout 3 and the bundle 2.

As the bundle 2 continues to move along the transport direction 7, the paper cutout's rear end 4, which continues to be under tension, is guided out of the claim 13c. This continues until the rear end 4 overlaps the front end 5 on the bundle's underside.

Having described the invention and a preferred embodiment thereof, what is new and secured by letters patent is: 

1-23. (canceled)
 24. An apparatus for forming bundles of individual liquid-filled containers by wrapping groups of said containers with a paper cutout, said apparatus comprising a bundling machine that comprises a transporter that conveys said bundle along a transport direction, a wrapper that receives said bundle from said transport direction and that is configured to surround said bundle with said paper cutout as said bundle proceeds along said transport direction through said wrapper such that a front end and a rear end of said paper cutout overlap, and a tensioner that is configured to be brought into engagement with said paper cutout to temporarily apply a tension to said rear end against said transport direction so as to cause said rear end to be held taut against said front end.
 25. The apparatus of claim 24, wherein said tensioner is adjacent to a side of said transporter that faces away from said bundle.
 26. The apparatus of claim 24, wherein said wrapper comprises a guide rod that brings said rear end into engagement with said tensioner.
 27. The apparatus of claim 24, wherein said wrapper comprises a compressed-air source and a guide rod that comprises compressed-air openings connected to said compressed-air source for displacing said paper cutout in a direction towards said tensioner.
 28. The apparatus of claim 24, further comprising a positioning unit that is configured to be brought into engagement with said rear end to thereby displace said rear end into said tensioner.
 29. The apparatus of claim 24, further comprising a compressed-air source and a compressed-air opening connected to said compressed air source.
 30. The apparatus of claim 24, wherein said tensioner comprises a device that secures said rear end of said paper cutout, said device being selected from the group consisting of a suction unit and a clamp.
 31. The apparatus of claim 24, further comprising a negative-pressure source and a contact surface that contacts said paper cutout, said contact surface being connected to said negative-pressure source.
 32. The apparatus of claim 24, further comprising a transport band and a contact surface that contacts said paper cutout, said transport band being disposed along a contact region at which said paper cutout contacts said contact surface.
 33. The apparatus of claim 24, wherein said tensioner comprises a clamp that comprises first and second clamp elements having respective first and second contact surfaces that are brought into contact on opposite sides of said paper cutout.
 34. The apparatus of claim 24, wherein said tensioner comprises a clamp that comprises first and second clamp elements having respective first and second contact surfaces that are separated by an adjustable gap.
 35. The apparatus of claim 24, wherein said tensioner comprises brushes that are separated by an adjustable distance, said brushes being disposed to contact said paper cutout on opposite sides thereof.
 36. The apparatus of claim 24, wherein said tensioner comprises rotating bodies that rotate about axes that are transverse to said transport direction and wherein said rotating bodies are separated by an adjustable gap that can be reduced so that said rotating bodies engage said paper cutout on opposite sides thereof with an adjustable tension.
 37. The apparatus of claim 24, wherein said wrapper comprises a guide rod and wherein said tensioner comprises first and second clamp elements, said first clamp element comprising an opening for temporarily receiving said guide rod.
 38. The apparatus of claim 24, wherein said tensioner is configured to sense a tension exerted on said paper cutout.
 39. The apparatus of claim 24, wherein said bundling machine is configured to secure said rear end to said front end.
 40. The apparatus of claim 24, wherein said bundling machine is configured to apply adhesive to secure said front and rear ends together.
 41. A method comprising forming a bundle of liquid-filled containers wherein forming said bundle comprises wrapping said bundle in a paper cutout having a front end and a rear end, wherein wrapping said bundle comprises transporting said bundle into a wrapper along a transport direction with said bundle resting on said front end, within said wrapper, temporarily applying tension to said rear end, said tension being in a direction opposite said transport direction, and forming an overlap between said rear end and said front end.
 42. The method of claim 41, further comprising, prior to transporting said bundle into said wrapper, grouping said liquid-filled containers on a cardboard tray.
 43. The method of claim 41, further comprising using a guide rod to bring said rear end of said paper cutout into engagement with a tensioner.
 44. The method of claim 41, further comprising using a positioning unit to displace said rear end into a tensioner.
 45. The method of claim 41, further comprising locking said read end into a tensioner by a force selected from the group consisting of a clamping force and a suction force.
 46. The method of claim 41, further comprising fixing said rear end to said front end with adhesive when said rear end and said front end overlap. 